The present invention relates to a microwave oven, and more particularly, to a device for cooling electric equipments in hooded microwave oven constructed to efficiently cool the electric equipments.
Hooded microwave oven is mounted on the top of a gas oven range, and has a hood function of discharging hot air or smoke generated from the gas oven range.
FIG. 1 is a perspective view showing a structure for cooling an electric equipment installation chamber of a conventional hooded microwave oven.
A cavity 1 and an electric equipment installation chamber 3 are formed in the interior of the conventional hooded microwave oven. Cooking is done in the interior of the cavity 1. Electric equipments which generate a microwave for performing the cooking in the interior of the cavity 1 are mounted on the electric equipment installation chamber 3. In order to cool the electric equipments in the electric equipment installation chamber 3, outer air is sucked through a suction grill 7. The suction grill 7 is formed at one side of a front surface of the microwave oven.
Meanwhile, a magnetron 8 for generating the microwave is mounted on a side surface T for partitioning the microwave oven into the cavity 1 and the electric equipment installation chamber 3. The magnetron 8 is mounted on a relatively upper portion of the electric equipment installation chamber 3. A wave-guide 9 is mounted for guiding the microwave generated by the magnetron 8 to the interior of the cavity 1 and is connected to the magnetron 8.
A bottom plate 5 defines a bottom surface of the electric equipment installation chamber 3. A high voltage transformer 10 and a high voltage capacitor 11 are mounted on the bottom plate 5. The high voltage transformer 10 enables the magnetron 8 to generate the microwave and induces a high voltage. The high voltage capacitor 11 is a portion for accumulating the high voltage. Here, when the microwave is generated, heat is relatively largely generated from the magnetron 8 and the high voltage transformer 10.
Meanwhile, an air guide 12 is provided for guiding the air that has just cooled the magnetron 8 to a ventilation motor assembly 13 to be described below. The air guide 12 enables the magnetron 8 to communicate with an inlet of the ventilation motor assembly 13.
The ventilation motor assembly 13 performs a hood function in hooded microwave oven, and a function of forming a flow of air for cooling the electric equipments in the electric equipment installation chamber 3.
Next, a partitioning wall 14 is installed across the top of the cavity 1 from the ventilation motor assembly 13 to the suction grill 7, and guides the air sucked through the suction grill 7 not to be scattered.
In the conventional hooded microwave oven as described above, the flow of air for cooling the electric equipments in the electric equipment installation chamber 3 is established as follows:
When the ventilation motor assembly 13 sucks an ambient air and discharges it to the outside, the interior of the microwave oven is under a low pressure state. Due to this, an outer air is sucked through the suction grill 7. At this time, a greater portion of the sucked air linearly flows toward the ventilation motor assembly 13. A portion of the air dissipates heat from the magnetron 8 attached to the side surface T of the electric equipment installation chamber 3, and the other portion of the air cools the high voltage transformer 10, the high voltage capacitor 11, etc. in a lower portion of the electric equipment installation chamber 3.
The air that has dissipated heat from the magnetron 8 is sucked through the air guide 12 to the ventilation motor assembly 13 positioned on the top side of the electric equipment installation chamber 3, and is discharged to the outside. The air that has dissipated heat from the electric equipments in the lower of the electric equipment installation chamber 3 flows upwardly, is sucked to the ventilation motor assembly 13 through a portion which is not covered by the air guide 12, and is then discharged to the outside.
However, there are some problems in the prior art as follows:
A majority of the air drawn through the suction grill 7 to the interior of the microwave oven by the ventilation motor assembly 13 linearly flows toward the ventilation motor assembly 13. Thus, since only little portion of the drawn air is transferred to electric equipments mounted on the bottom plate 5, cooling thereof is not sufficient.
That is, the velocity of the air drawn from the suction grill 7 having a smaller area to the interior of the electric equipment installation chamber 3 having a greater volume is abruptly lowered and a majority of the introduced air flows directly toward the ventilation motor assembly 13.
Particularly, since the air transferred to the high voltage transformer 10, etc. positioned at the lower portion of the electric equipment installation chamber 3 flows over a long distance, it slows down and the heat dissipating efficiency thereof is deteriorated. Therefore, after the microwave oven has been used for a long time, a reliability problem of the electric equipments due to overheat may be issued.
On the other hand, in order to solve the above reliability problem of the electric equipments, the electric equipments should be designed and manufactured to minimize an amount of heat generation. This results in high manufacturing costs thereof.
Further, in order to increase an amount of the sucked air and the velocity of the air by increasing the suction force of the ventilation motor assembly 13, the rotation speed of a ventilation motor should be increased. This also results in much noise and increased consumption of power.
Therefore, the present invention is conceived to solve the above problems. It is an object of the present invention to maximize efficiency of cooling electric equipments.
It is another object of the present invention to provide a microwave oven wherein less noise is generated and consumption of power is low.
According to features of the present invention for achieving the above objects, there is provided a device for cooling electric equipments of hooded microwave oven, comprising: a ventilation motor assembly mounted on the top of a cavity, for forming both a flow of air for a hood function and a flow of air for dissipating heat from the electric equipments; and a suction grill which is a passage through which outer air is sucked to the top of the cavity by suction force of the ventilation motor assembly. The electric equipments are positioned in a flow path of the air that is sucked through the suction grill and flows to the ventilation motor assembly.
A bottom plate for defining a bottom surface of an electric equipment installation chamber, in which the electric equipments are mounted, may be mounted at a top end of the cavity. Thus, the electric equipments are positioned in the flow path of the air flowing from the suction grill to the ventilation motor assembly.
A magnetron of the electric equipments may be mounted on a side surface of the cavity. A passage hole for guiding the air to the magnetron may be formed on the bottom plate. The air that has passed by the magnetron may be guided to the ventilation motor assembly by an air guide.
The magnetron of the electric equipments may be mounted on the bottom plate and adjacent to an inlet of the ventilation motor assembly.
A wave-guide for guiding a microwave generated by the magnetron to the interior of the cavity may be mounted on a bottom surface of the magnetron and on the side surface of the cavity.
According to the above constitution, since the flow path of the air for cooling the electric equipments is formed in one direction, its cooling efficiency is maximized and the reliability of the electric equipments is guaranteed. In addition, noise generated from the ventilation motor assembly can be minimized.